Seeker

What Food Tastes Like to a Cat

Cats have a much more refined sense of taste than previously thought, with new research showing that felines are highly sensitive to bitter flavors.

The discovery could help explain why cats so often turn up their noses at certain foods that may be fortified with bitter-tasting vitamins and minerals. The findings, published in the journal PLOS ONE, also provide intriguing clues on how sense of taste evolved in all mammals, including humans.

"Cats are known as picky eaters," said Monell Center molecular biologist and study lead author Peihua Jiang. "Now that we know that they can taste different bitters, our work may lead to better formulations of cat food that eliminate the bitter off-taste associated with certain flavors and nutrients."

For the study, Jiang and colleagues examined DNA from domestic cats and identified 12 different genes for cat bitter receptors. The scientists then probed the receptor cells to see if one or more of 25 bitter-tasting chemicals activated them.

The researchers confirmed that at least seven of the identified 12 receptors did indeed have the ability to detect one or more bitter chemicals. It is likely that the other five receptors have this ability too, but that they may respond to bitter compounds not included in this particular study.

Prior research determined that cats are unable to detect sugars. Other carnivores, such as sea lions and spotted hyenas, also lost their ability to taste sweet things. These mammals might have a heightened ability to detect salty and savory flavors.

Cats also seem to go for calorie-dense foods and foods with different textures, helping to explain why savory cat treats with slightly crunchy exteriors and soft interiors appear to be a universal feline fave.

A long-standing theory has held that the ability to taste bitter flavors evolved to protect humans and other animals from ingesting poisonous plants. That is now being questioned since, aside from the occasional chomping on kitty grass, cats go for meat and not plant products.

"Alternate physiological roles for bitter receptors may be an important driving force molding bitter receptor number and function," co-author Gary Beauchamp said. "For example, recent Monell-related findings show that bitter receptors also are involved in protecting us against internal toxins, including bacteria related to respiratory diseases."

He added that "bitter taste could exist to minimize intake of toxic compounds from skin and other components of certain prey species, such as invertebrates, reptiles and amphibians."

In the study, the researchers also point out that other mammals have multiple receptors dedicated to tasting bitter flavors. Dogs have 15, ferrets have 14, giant pandas have 16 and polar bears have 13.

There's a new addition to Smithsonian National Zoo's Small Mammal House: a female sand cat named Lulu. She was brought in as a mate for the resident male Thor. The hope is that kittens will soon follow.
Let's learn a bit about sand cats, starting with what they are, and then find out how the two are getting along.

Here Thor says "Hello" in sand cat. As their name implies, sand cats live in deserts and are the only cats to live primarily in such environments. They live in deserts of Central and Southwest Asia, as well as those of North Africa.
They're well suited to the hot and cold swings of temperature in the desert and will burrow into the sand to keep cool.
Smithsonian researchers say they're tough animals to study, in part because their presence is hard to spot. They have fur on their foot pads and leave barely a trace in the desert sand.

Here's Lulu striking a pose. (Hint; you can tell it's her from her oval-shaped face, compared to Thor, whose mug is a bit more horizontally inclined.)
Early reports are that Lulu has already established herself as the more dominant and feisty of the two, while Thor is outgoing with zoo staff and is happy to try his best in training sessions.

Zoo staff say they help the cats keep up with their natural behaviors by hiding some of their food in puzzle feeders, as shown here. It keeps them busy remembering how to claw and dig at things to get a meal.

If the stylish pair produces kittens, it will be the first experience of parenthood for either cat. Their introduction went "incredibly well," according to zoo staff. So there may well be babies in the offing!
In fact, the zoo has recently separated Lulu from Thor, while veterinarians determine whether or not she is indeed pregnant. Thor's presence, say staff, could stress out Lulu if she's going to have kittens.
Every little new kitten helps the species, too. Sand cats are currently listed as "Near Threatened" on the International Union for the Conservation of Nature's "red list" of threatened species.